Constantine I. AE4. Constantinople.

Obv: CONSTANTI-NVS MAX AVG, rosette-diademed, draped, cuirassed bust right. 
Rev: GLOR-IA EXERC-ITVS, two soldiers holding spears and 
shields with one standard between them. O on banner.

Mintmark CONS delta.
RIC VII Constantinople 137, rated R1.

From Dane's collection, August 2010.

Known mintmarks for this RIC number:
CONSA
CONS delta
CONSH

All these three officina letters look very similar
and could in fact all be from a single officina with
the letter engraved in different ways.